Beginning Country Level Models and Individual Country Linear Fits
Fitting Individual Countries Time Series Trajectories
Lets do some stuff from Solomon Kurz’s other bookdown, Applied Longitudinal Data Analysis in brms and the tidyverse, to see if we can visualize our target variable a bit better. I’m also using some techniques from Hadley Wickham’s nice youtube video, Managing many models with R.
#read the file, if you dont have it from the previous markdown.
aei <- read.csv("/Volumes/RachelExternal/Thesis/Data_upload_for_CL/AEI_Std.csv")
aei <- aei[,-1]With Priors
by_ISO <-
aei %>%
filter(!is.na(irrperc)) %>%
group_by(ISO) %>%
nest()Prior Prediction
Doing a little prior plotting, I’ve messed around a bit and settled on some semi-sensible priors assuming a gaussian distribution for both the parameter and slope. I am assuming that our intercept is normally distributed with around a mean of 2 and a standard variation of 2, our beta coef is centered around 0.01 with a sd of 0.1. This produces irrperc values within an acceptable range (roughly 0-15%). There are some negative values here. Perhaps a prior that is bounded by 0 would be a better fit for this, but experiments with log normal distributions have proved difficult. Also, none of the countries have negative trajectories of irrigation expansion, but some do have a decrease towards the end of the study period.
set.seed(17)
N <- 50
a <- rnorm(N , 2, 2)
b <- rnorm( N , 0., 0.1 )
plot( NULL , xlim=range(aei$yearcount) , ylim=c(-50,50) , xlab="year" , ylab="Irrigation Percentage" )
abline( h=0 , lty=2 )
for ( i in 1:N ) curve( a[i] + b[i]*x ,
from=min(aei$yearcount) , to=max(aei$yearcount) , add=TRUE , col=col.alpha("black",0.2) )
These don’t look too bad. There are some lines that predict negative values but in general they seem to be positive and have a very general upward slope.
First Model
Here were fitting the first model which is just dependent on the year count and the priors we specified above..
\[ \begin{aligned} irrperc_c &\sim N(\mu_c, \sigma_c) \\ \mu_c &= \alpha_c + \beta_c*yearcount \\ \alpha_c &\sim N(2,2) \\ \beta_c &\sim N(0.01, 0.1) \\ \sigma_c &\sim exp(1) \end{aligned} \]
I won’t use the first country, as we have 0 for the irrigation percent. AFG is the second country, and there is some evolution.
AFG_norm_yearcount <-
brm(data = by_ISO$data[[2]], #AFG
formula = irrperc ~ yearcount,
control = list(adapt_delta = 0.99),
prior = c(prior(normal(2,2), class = Intercept),
prior(normal(0.01, 0.1), class = b),
prior(exponential(1), class = sigma)),
iter = 4000, chains = 4, cores = 4,
seed = 17,
file = "/Volumes/RachelExternal/Thesis/Thesis/fits/CL_Fits/AFG_norm_d_yearcount13")Yep looks fine here! Check these posterior and the priors, just to see that brms is putting them in the right place…
print(AFG_norm_yearcount, digits = 4)## Family: gaussian
## Links: mu = identity; sigma = identity
## Formula: irrperc ~ yearcount
## Data: by_ISO$data[[2]] (Number of observations: 13)
## Samples: 4 chains, each with iter = 4000; warmup = 2000; thin = 1;
## total post-warmup samples = 8000
##
## Population-Level Effects:
## Estimate Est.Error l-95% CI u-95% CI Rhat Bulk_ESS Tail_ESS
## Intercept 0.7944 0.1916 0.4149 1.1780 1.0020 4598 3814
## yearcount 0.0456 0.0031 0.0394 0.0515 1.0020 5025 3464
##
## Family Specific Parameters:
## Estimate Est.Error l-95% CI u-95% CI Rhat Bulk_ESS Tail_ESS
## sigma 0.3235 0.0774 0.2108 0.5108 1.0003 3621 3607
##
## Samples were drawn using sampling(NUTS). For each parameter, Bulk_ESS
## and Tail_ESS are effective sample size measures, and Rhat is the potential
## scale reduction factor on split chains (at convergence, Rhat = 1).prior_summary(AFG_norm_yearcount)## prior class coef group resp dpar nlpar bound source
## normal(0.01, 0.1) b user
## normal(0.01, 0.1) b yearcount (vectorized)
## normal(2, 2) Intercept user
## exponential(1) sigma userYep, all good.
Now for the first part of the master plan, apply this to all countries, resulting in individual country trajectories, individual slopes and intercepts, but calculated only with the 8 data points for each country. Use map here to apply this to every ISO.
models <-
by_ISO %>%
mutate(model = map(data, ~update(AFG_norm_yearcount, newdata = ., seed = 2)))This runs, and for some of the models it yells that things didn’t converge.. and I’m just going to leave it, as this is not really the most importatnt part.
Calculation of Mean Structure
Again, using the code suggested form S. Kurz, the intercept/intercept standard deviation and the rate of change/rate of change sd can be extracted from the estimates and coeffs.
mean_structure <-
models %>%
mutate(coefs = map(model, ~ posterior_summary(.)[1:2, 1:2] %>%
data.frame() %>%
rownames_to_column("coefficients"))) %>%
unnest(coefs) %>%
select(-data, -model) %>%
unite(temp, Estimate, Est.Error) %>%
pivot_wider(names_from = coefficients,
values_from = temp) %>%
separate(b_Intercept, into = c("init_stat_est", "init_stat_sd"), sep = "_") %>%
separate(b_yearcount, into = c("rate_change_est", "rate_change_sd"), sep = "_") %>%
mutate_if(is.character, ~ as.double(.) %>% round(digits = 2)) %>%
ungroup()Calculation of Residual Variance
residual_variance <-
models %>%
mutate(residual_variance = map_dbl(model, ~ posterior_summary(.)[3, 1])^2) %>%
mutate_if(is.double, round, digits = 2) %>%
select(ISO, residual_variance)Calculation of Bayesian \(R^2\)
r2 <-
models %>%
mutate(r2 = map_dbl(model, ~ bayes_R2(., robust = T)[1])) %>%
mutate_if(is.double, round, digits = 2) %>%
select(ISO, r2)Fit
table <-
models %>%
unnest(data) %>%
group_by(ISO) %>%
slice(1) %>%
select(ISO) %>%
left_join(mean_structure, by = "ISO") %>%
left_join(residual_variance, by = "ISO") %>%
left_join(r2, by = "ISO") %>%
rename(residual_var = residual_variance) %>%
select(ISO, init_stat_est:r2, everything()) %>%
ungroup()
table %>%
knitr::kable()| ISO | init_stat_est | init_stat_sd | rate_change_est | rate_change_sd | residual_var | r2 |
|---|---|---|---|---|---|---|
| ABW | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| AFG | 0.79 | 0.19 | 0.05 | 0.00 | 0.11 | 0.96 |
| AGO | 0.04 | 0.00 | 0.00 | 0.00 | 0.00 | 0.91 |
| ALB | -2.20 | 1.40 | 0.17 | 0.02 | 6.43 | 0.85 |
| AND | -0.09 | 0.07 | 0.00 | 0.00 | 0.02 | 0.53 |
| ARE | -0.37 | 0.45 | 0.02 | 0.01 | 0.60 | 0.57 |
| ARG | 0.25 | 0.04 | 0.00 | 0.00 | 0.00 | 0.86 |
| ARM | 2.86 | 0.68 | 0.09 | 0.01 | 1.38 | 0.87 |
| ASM | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| ATG | -0.09 | 0.13 | 0.01 | 0.00 | 0.05 | 0.47 |
| AUS | -0.06 | 0.03 | 0.01 | 0.00 | 0.00 | 0.94 |
| AUT | 0.30 | 0.14 | 0.01 | 0.00 | 0.06 | 0.61 |
| AZE | 5.17 | 0.75 | 0.13 | 0.01 | 1.64 | 0.94 |
| BDI | -0.15 | 0.08 | 0.01 | 0.00 | 0.02 | 0.88 |
| BEL | 0.29 | 0.12 | 0.00 | 0.00 | 0.04 | 0.39 |
| BEN | -0.03 | 0.01 | 0.00 | 0.00 | 0.00 | 0.84 |
| BFA | -0.02 | 0.01 | 0.00 | 0.00 | 0.00 | 0.77 |
| BGD | -7.27 | 3.51 | 0.26 | 0.07 | 59.18 | 0.58 |
| BGR | 0.18 | 1.91 | 0.07 | 0.03 | 13.29 | 0.28 |
| BHR | -0.02 | 0.69 | 0.04 | 0.01 | 1.51 | 0.60 |
| BHS | -0.03 | 0.02 | 0.00 | 0.00 | 0.00 | 0.73 |
| BIH | 0.03 | 0.01 | 0.00 | 0.00 | 0.00 | 0.09 |
| BLR | -0.09 | 0.10 | 0.01 | 0.00 | 0.03 | 0.79 |
| BLZ | -0.04 | 0.02 | 0.00 | 0.00 | 0.00 | 0.79 |
| BMU | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| BOL | -0.01 | 0.01 | 0.00 | 0.00 | 0.00 | 0.90 |
| BRA | -0.11 | 0.05 | 0.00 | 0.00 | 0.01 | 0.81 |
| BRB | -3.00 | 1.42 | 0.14 | 0.02 | 6.81 | 0.74 |
| BRN | -0.06 | 0.03 | 0.00 | 0.00 | 0.00 | 0.73 |
| BTN | -0.03 | 0.11 | 0.01 | 0.00 | 0.03 | 0.79 |
| BWA | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.76 |
| CAF | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.55 |
| CAN | -0.01 | 0.01 | 0.00 | 0.00 | 0.00 | 0.91 |
| CHE | 0.58 | 0.14 | 0.01 | 0.00 | 0.06 | 0.46 |
| CHL | 0.91 | 0.15 | 0.02 | 0.00 | 0.06 | 0.84 |
| CHN | 0.93 | 0.37 | 0.06 | 0.01 | 0.41 | 0.91 |
| CIV | -0.05 | 0.03 | 0.00 | 0.00 | 0.00 | 0.83 |
| CMR | -0.01 | 0.01 | 0.00 | 0.00 | 0.00 | 0.84 |
| COD | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.76 |
| COG | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.79 |
| COL | -0.18 | 0.09 | 0.01 | 0.00 | 0.02 | 0.85 |
| COM | -0.02 | 0.02 | 0.00 | 0.00 | 0.00 | 0.63 |
| CPV | 0.10 | 0.03 | 0.01 | 0.00 | 0.00 | 0.95 |
| CRI | -0.16 | 0.20 | 0.02 | 0.00 | 0.12 | 0.83 |
| CUB | -1.51 | 0.80 | 0.11 | 0.01 | 1.96 | 0.87 |
| CYM | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| CYP | 0.67 | 0.30 | 0.04 | 0.00 | 0.28 | 0.89 |
| CZE | -0.01 | 0.31 | 0.01 | 0.01 | 0.29 | 0.48 |
| DEU | 0.87 | 0.68 | 0.02 | 0.01 | 1.38 | 0.23 |
| DJI | -0.01 | 0.01 | 0.00 | 0.00 | 0.00 | 0.79 |
| DMA | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| DNK | -2.65 | 1.29 | 0.14 | 0.02 | 5.35 | 0.80 |
| DOM | -0.78 | 0.27 | 0.07 | 0.00 | 0.22 | 0.97 |
| DZA | 0.04 | 0.02 | 0.00 | 0.00 | 0.00 | 0.74 |
| ECU | -0.50 | 0.16 | 0.04 | 0.00 | 0.07 | 0.97 |
| EGY | 2.13 | 0.08 | 0.01 | 0.00 | 0.02 | 0.93 |
| ERI | -0.04 | 0.03 | 0.00 | 0.00 | 0.00 | 0.78 |
| ESP | 1.91 | 0.32 | 0.05 | 0.01 | 0.31 | 0.92 |
| EST | 0.00 | 0.06 | 0.00 | 0.00 | 0.01 | 0.26 |
| ETH | -0.05 | 0.04 | 0.00 | 0.00 | 0.00 | 0.77 |
| FIN | -0.05 | 0.04 | 0.00 | 0.00 | 0.00 | 0.75 |
| FJI | -0.04 | 0.03 | 0.00 | 0.00 | 0.00 | 0.70 |
| FRA | -0.44 | 0.49 | 0.05 | 0.01 | 0.70 | 0.82 |
| FRO | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| FSM | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| GAB | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.78 |
| GBR | -0.09 | 0.10 | 0.01 | 0.00 | 0.03 | 0.84 |
| GEO | 0.76 | 0.30 | 0.06 | 0.01 | 0.27 | 0.95 |
| GHA | -0.03 | 0.02 | 0.00 | 0.00 | 0.00 | 0.77 |
| GIB | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| GIN | -0.04 | 0.04 | 0.00 | 0.00 | 0.00 | 0.87 |
| GLP | -0.70 | 0.51 | 0.03 | 0.01 | 0.76 | 0.65 |
| GMB | 0.07 | 0.02 | 0.00 | 0.00 | 0.00 | 0.53 |
| GNB | 0.19 | 0.04 | 0.01 | 0.00 | 0.01 | 0.92 |
| GNQ | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| GRC | -0.60 | 0.64 | 0.12 | 0.01 | 1.24 | 0.93 |
| GRD | -0.17 | 0.14 | 0.01 | 0.00 | 0.05 | 0.53 |
| GRL | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| GTM | -0.06 | 0.11 | 0.01 | 0.00 | 0.04 | 0.87 |
| GUF | -0.01 | 0.01 | 0.00 | 0.00 | 0.00 | 0.71 |
| GUM | -0.12 | 0.12 | 0.00 | 0.00 | 0.04 | 0.36 |
| GUY | 0.12 | 0.03 | 0.01 | 0.00 | 0.00 | 0.97 |
| HND | 0.01 | 0.04 | 0.01 | 0.00 | 0.01 | 0.93 |
| HRV | 0.01 | 0.04 | 0.00 | 0.00 | 0.01 | 0.18 |
| HTI | 0.01 | 0.15 | 0.04 | 0.00 | 0.06 | 0.97 |
| HUN | -0.16 | 0.72 | 0.04 | 0.01 | 1.58 | 0.55 |
| IDN | 0.84 | 0.21 | 0.02 | 0.00 | 0.14 | 0.83 |
| IND | 4.67 | 1.86 | 0.12 | 0.03 | 10.43 | 0.71 |
| IRL | 0.03 | 0.01 | 0.00 | 0.00 | 0.00 | 0.35 |
| IRN | 1.00 | 0.07 | 0.04 | 0.00 | 0.02 | 0.99 |
| IRQ | -0.46 | 0.76 | 0.08 | 0.01 | 1.84 | 0.82 |
| ISL | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| ISR | -0.06 | 0.83 | 0.11 | 0.01 | 2.15 | 0.87 |
| ITA | 4.29 | 0.36 | 0.10 | 0.01 | 0.39 | 0.97 |
| JAM | 0.94 | 0.10 | 0.02 | 0.00 | 0.03 | 0.93 |
| JOR | -0.03 | 0.08 | 0.01 | 0.00 | 0.02 | 0.85 |
| JPN | 8.12 | 0.21 | 0.00 | 0.00 | 0.13 | 0.06 |
| KAZ | 0.47 | 0.09 | 0.01 | 0.00 | 0.02 | 0.82 |
| KEN | -0.02 | 0.02 | 0.00 | 0.00 | 0.00 | 0.79 |
| KGZ | 1.88 | 0.30 | 0.04 | 0.00 | 0.26 | 0.91 |
| KHM | -0.29 | 0.22 | 0.02 | 0.00 | 0.14 | 0.79 |
| KIR | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| KNA | 0.05 | 0.00 | 0.00 | 0.00 | 0.00 | 0.73 |
| KOR | 3.02 | 0.56 | 0.08 | 0.01 | 0.94 | 0.88 |
| KWT | -0.11 | 0.08 | 0.00 | 0.00 | 0.02 | 0.61 |
| LAO | -0.27 | 0.18 | 0.01 | 0.00 | 0.10 | 0.69 |
| LBN | -0.15 | 0.59 | 0.11 | 0.01 | 1.05 | 0.93 |
| LBR | -0.01 | 0.00 | 0.00 | 0.00 | 0.00 | 0.84 |
| LBY | -0.02 | 0.03 | 0.00 | 0.00 | 0.00 | 0.83 |
| LCA | -1.23 | 0.68 | 0.06 | 0.01 | 1.41 | 0.76 |
| LIE | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| LKA | 1.87 | 0.24 | 0.08 | 0.00 | 0.17 | 0.98 |
| LSO | -0.02 | 0.01 | 0.00 | 0.00 | 0.00 | 0.81 |
| LTU | -0.01 | 0.13 | 0.00 | 0.00 | 0.05 | 0.28 |
| LUX | 1.28 | 0.25 | -0.02 | 0.00 | 0.19 | 0.66 |
| LVA | 0.01 | 0.07 | 0.00 | 0.00 | 0.01 | 0.24 |
| MAR | 0.96 | 0.10 | 0.02 | 0.00 | 0.03 | 0.96 |
| MCO | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| MDA | -1.99 | 0.81 | 0.12 | 0.01 | 2.02 | 0.90 |
| MDG | -0.20 | 0.17 | 0.02 | 0.00 | 0.08 | 0.88 |
| MDV | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| MEX | 0.25 | 0.16 | 0.03 | 0.00 | 0.07 | 0.95 |
| MHL | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| MKD | -1.02 | 0.56 | 0.07 | 0.01 | 0.93 | 0.87 |
| MLI | -0.02 | 0.03 | 0.00 | 0.00 | 0.00 | 0.58 |
| MLT | -0.67 | 0.92 | 0.06 | 0.01 | 2.64 | 0.65 |
| MMR | -0.52 | 0.25 | 0.03 | 0.00 | 0.18 | 0.89 |
| MNG | -0.01 | 0.01 | 0.00 | 0.00 | 0.00 | 0.76 |
| MOZ | 0.00 | 0.01 | 0.00 | 0.00 | 0.00 | 0.91 |
| MRT | 0.01 | 0.00 | 0.00 | 0.00 | 0.00 | 0.85 |
| MTQ | -0.38 | 0.69 | 0.06 | 0.01 | 1.43 | 0.72 |
| MUS | -1.05 | 0.49 | 0.12 | 0.01 | 0.69 | 0.96 |
| MWI | -0.14 | 0.09 | 0.01 | 0.00 | 0.02 | 0.67 |
| MYS | 0.32 | 0.03 | 0.01 | 0.00 | 0.00 | 0.98 |
| NAM | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.85 |
| NCL | -0.10 | 0.07 | 0.00 | 0.00 | 0.01 | 0.70 |
| NER | -0.01 | 0.01 | 0.00 | 0.00 | 0.00 | 0.75 |
| NGA | 0.15 | 0.02 | 0.00 | 0.00 | 0.00 | 0.79 |
| NIC | -0.06 | 0.06 | 0.01 | 0.00 | 0.01 | 0.88 |
| NLD | 2.14 | 2.07 | 0.12 | 0.03 | 14.82 | 0.54 |
| NOR | -0.04 | 0.04 | 0.00 | 0.00 | 0.01 | 0.77 |
| NPL | -2.06 | 0.99 | 0.10 | 0.02 | 3.02 | 0.78 |
| NRU | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| NZL | 0.00 | 0.18 | 0.02 | 0.00 | 0.10 | 0.89 |
| OMN | 0.03 | 0.02 | 0.00 | 0.00 | 0.00 | 0.78 |
| PAK | -2.97 | 1.95 | 0.25 | 0.03 | 12.77 | 0.89 |
| PAN | 0.03 | 0.04 | 0.01 | 0.00 | 0.00 | 0.89 |
| PER | 0.21 | 0.09 | 0.01 | 0.00 | 0.02 | 0.91 |
| PHL | -0.41 | 0.33 | 0.07 | 0.01 | 0.33 | 0.94 |
| PLW | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| PNG | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| POL | 0.03 | 0.19 | 0.01 | 0.00 | 0.11 | 0.46 |
| PRI | 1.63 | 0.49 | 0.02 | 0.01 | 0.71 | 0.52 |
| PRK | -0.18 | 0.98 | 0.12 | 0.02 | 3.24 | 0.85 |
| PRT | 2.54 | 0.83 | 0.07 | 0.01 | 2.09 | 0.76 |
| PRY | 0.00 | 0.01 | 0.00 | 0.00 | 0.00 | 0.95 |
| PSE | 0.20 | 0.28 | 0.04 | 0.00 | 0.23 | 0.90 |
| PYF | -0.08 | 0.06 | 0.00 | 0.00 | 0.01 | 0.53 |
| QAT | -0.29 | 0.18 | 0.01 | 0.00 | 0.09 | 0.68 |
| REU | -0.73 | 0.43 | 0.05 | 0.01 | 0.56 | 0.87 |
| ROU | -2.46 | 2.03 | 0.13 | 0.03 | 14.31 | 0.54 |
| RUS | -0.03 | 0.05 | 0.00 | 0.00 | 0.01 | 0.64 |
| RWA | -0.06 | 0.04 | 0.00 | 0.00 | 0.00 | 0.82 |
| SAU | -0.11 | 0.10 | 0.01 | 0.00 | 0.03 | 0.79 |
| SDN | 0.03 | 0.07 | 0.01 | 0.00 | 0.01 | 0.93 |
| SEN | 0.19 | 0.04 | 0.00 | 0.00 | 0.00 | 0.81 |
| SGP | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| SLB | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| SLE | -0.10 | 0.06 | 0.01 | 0.00 | 0.01 | 0.80 |
| SLV | -0.46 | 0.20 | 0.03 | 0.00 | 0.12 | 0.91 |
| SMK | -0.05 | 0.29 | 0.02 | 0.00 | 0.27 | 0.63 |
| SMR | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| SOM | 0.04 | 0.03 | 0.00 | 0.00 | 0.00 | 0.85 |
| STP | 4.72 | 0.62 | 0.07 | 0.01 | 1.20 | 0.83 |
| SUR | -0.03 | 0.02 | 0.00 | 0.00 | 0.00 | 0.92 |
| SVK | -0.99 | 0.56 | 0.05 | 0.01 | 1.00 | 0.75 |
| SVN | -0.09 | 0.13 | 0.01 | 0.00 | 0.05 | 0.43 |
| SWE | 0.03 | 0.06 | 0.00 | 0.00 | 0.01 | 0.51 |
| SWZ | -0.55 | 0.30 | 0.04 | 0.00 | 0.27 | 0.88 |
| SYC | -0.11 | 0.12 | 0.00 | 0.00 | 0.04 | 0.29 |
| SYR | -0.73 | 0.61 | 0.07 | 0.01 | 1.14 | 0.85 |
| TCA | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| TCD | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.80 |
| TGO | -0.02 | 0.02 | 0.00 | 0.00 | 0.00 | 0.64 |
| THA | -1.44 | 0.77 | 0.12 | 0.01 | 1.90 | 0.90 |
| TJK | 0.71 | 0.19 | 0.05 | 0.00 | 0.11 | 0.97 |
| TKM | -0.36 | 0.35 | 0.04 | 0.01 | 0.35 | 0.86 |
| TLS | 0.12 | 0.24 | 0.02 | 0.00 | 0.16 | 0.69 |
| TON | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| TTO | 0.00 | 0.06 | 0.01 | 0.00 | 0.01 | 0.91 |
| TUN | 0.13 | 0.25 | 0.02 | 0.00 | 0.18 | 0.81 |
| TUR | -0.46 | 0.56 | 0.07 | 0.01 | 1.00 | 0.84 |
| TUV | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| TWN | 9.67 | 1.33 | 0.05 | 0.02 | 4.65 | 0.46 |
| TZA | -0.03 | 0.03 | 0.00 | 0.00 | 0.00 | 0.80 |
| UGA | -0.01 | 0.01 | 0.00 | 0.00 | 0.00 | 0.86 |
| UKR | -0.95 | 0.46 | 0.06 | 0.01 | 0.64 | 0.87 |
| URY | -0.30 | 0.16 | 0.01 | 0.00 | 0.08 | 0.78 |
| USA | 0.72 | 0.10 | 0.03 | 0.00 | 0.03 | 0.97 |
| UZB | 2.21 | 0.39 | 0.09 | 0.01 | 0.46 | 0.95 |
| VCT | -0.62 | 0.41 | 0.04 | 0.01 | 0.50 | 0.78 |
| VEN | -0.06 | 0.05 | 0.01 | 0.00 | 0.01 | 0.90 |
| VGB | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| VIR | -0.10 | 0.07 | 0.00 | 0.00 | 0.02 | 0.67 |
| VNM | -0.99 | 1.16 | 0.12 | 0.02 | 4.39 | 0.78 |
| VUT | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| WSM | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 |
| YEM | 0.08 | 0.10 | 0.01 | 0.00 | 0.03 | 0.77 |
| ZAF | 0.08 | 0.03 | 0.01 | 0.00 | 0.00 | 0.99 |
| ZMB | -0.05 | 0.04 | 0.00 | 0.00 | 0.00 | 0.58 |
| ZWE | -0.10 | 0.05 | 0.00 | 0.00 | 0.01 | 0.84 |
Plotting
abline <-
by_ISO %>%
unnest(data) %>%
ggplot(aes(x = yearcount, y = irrperc, group = ISO)) +
geom_point() +
geom_abline(data = mean_structure,
aes(intercept = init_stat_est,
slope = rate_change_est, group = ISO),
color = "blue") +
scale_x_continuous() +
coord_cartesian(ylim = c(0, 35)) +
theme(panel.grid = element_blank()) +
facet_wrap(~ISO, ncol = 2)
ggsave("/Volumes/RachelExternal/Thesis/Thesis/abline.png", abline, height = 200,limitsize = FALSE, dpi = 300 )## Saving 7 x 200 in image
Some of these countries don’t have fantastic fits. ALB, BGD, BGR, BRB, CUB, DNK, IND, NLD, PAK, ROU, have some issues.
Using No Priors
What if I do this again with no priors… and see if it fits better for the countries with more extreme increases in irrigated area over time. Ive run the same setup as above with the calculation of the mean, variance and bayesian \(R^2\). Below I’ve graphed the fits for the problem countries (ALB, BGD, BGR, BRB, CUB, DNK, IND, NLD, PAK, ROU). ### The No Prior Model
AFG_norm_nopri_d_yearcount <-
brm(data = by_ISO$data[[2]],
formula = irrperc ~ yearcount,
control = list(adapt_delta = 0.99),
iter = 4000, chains = 4, cores = 4,
seed = 17,
file = "/Volumes/RachelExternal/Thesis/Thesis/fits/AFG_norm_nopri_d_yearcount13")
models_noprior <-
by_ISO %>%
mutate(model = map(data, ~update(AFG_norm_nopri_d_yearcount, newdata = ., seed = 2)))Calculation of Statistics
mean_structure_noprior <-
models_noprior %>%
mutate(coefs = map(model, ~ posterior_summary(.)[1:2, 1:2] %>%
data.frame() %>%
rownames_to_column("coefficients"))) %>%
unnest(coefs) %>%
select(-data, -model) %>%
unite(temp, Estimate, Est.Error) %>%
pivot_wider(names_from = coefficients,
values_from = temp) %>%
separate(b_Intercept, into = c("init_stat_est", "init_stat_sd"), sep = "_") %>%
separate(b_yearcount, into = c("rate_change_est", "rate_change_sd"), sep = "_") %>%
mutate_if(is.character, ~ as.double(.) %>% round(digits = 2)) %>%
ungroup()
residual_variance_noprior <-
models_noprior %>%
mutate(residual_variance = map_dbl(model, ~ posterior_summary(.)[3, 1])^2) %>%
mutate_if(is.double, round, digits = 2) %>%
select(ISO, residual_variance)
r2_noprior <-
models_noprior %>%
mutate(r2 = map_dbl(model, ~ bayes_R2(., robust = T)[1])) %>%
mutate_if(is.double, round, digits = 2) %>%
select(ISO, r2)Plotting
abline_noprior <-
by_ISO %>%
subset(., c(ISO == "ALB"| ISO == "BGD"|ISO == "BGR"| ISO == "BRB"|
ISO == "CUB"|ISO == "DNK"|ISO == "IND"|
ISO == "NLD"|ISO == "PAK"|ISO == "ROU")) %>%
unnest(data) %>%
ggplot(aes(x = yearcount, y = irrperc, group = ISO)) +
geom_point() +
geom_abline(data = subset(mean_structure_noprior, c(ISO == "ALB"|
ISO == "BGD"|
ISO == "BGR"|
ISO == "BRB"|
ISO == "CUB"|
ISO == "DNK"|
ISO == "IND"|
ISO == "NLD"|
ISO == "PAK"|
ISO == "ROU")),
aes(intercept = init_stat_est,
slope = rate_change_est, group = ISO),
color = "blue") +
scale_x_continuous() +
coord_cartesian(ylim = c(0, 35)) +
theme(panel.grid = element_blank()) +
facet_wrap(~ISO, ncol = 2)
ggsave("/Volumes/RachelExternal/Thesis/Thesis/abline_noprior.png", abline_noprior, dpi = 300 )
Individual Country Fits with no priors specified
Whoa, ok so these countries are fit way way better. This makes sense though, because if the model is being refit for each country then the priors can fluctuate much more. in the first run, I limited the priors to a pretty narrow slope that wasn’t helpful for countries that have expansion trajectories that increase quicker than the range I specified in the prior. If brms is behaving like I expect it to behave, its fitting a uniform prior for the slope and a student t distribution for the intercept, FOR EACH COUNTRY. I could go back and weaken the priors chosen for fit1 but what I’m doing here is not that important.
Prior vs. No Prior Fits
Lets check the table, first the problem countries fit without a prior.
| ISO | init_stat_est | init_stat_sd | rate_change_est | rate_change_sd | residual_var | r2 |
|---|---|---|---|---|---|---|
| ALB | -2.25 | 1.56 | 0.18 | 0.03 | 7.04 | 0.86 |
| BGD | -9.91 | 3.90 | 0.39 | 0.06 | 43.55 | 0.80 |
| BGR | 0.19 | 2.24 | 0.08 | 0.04 | 15.56 | 0.31 |
| BRB | -3.14 | 1.57 | 0.14 | 0.03 | 7.76 | 0.76 |
| CUB | -1.54 | 0.84 | 0.11 | 0.01 | 2.17 | 0.88 |
| DNK | -2.74 | 1.42 | 0.14 | 0.02 | 6.00 | 0.81 |
| IND | 5.80 | 1.64 | 0.13 | 0.03 | 7.85 | 0.74 |
| NLD | 2.81 | 2.21 | 0.13 | 0.04 | 14.31 | 0.58 |
| PAK | -2.53 | 1.83 | 0.28 | 0.03 | 9.51 | 0.91 |
| ROU | -2.79 | 2.27 | 0.15 | 0.04 | 16.16 | 0.60 |
And now the original fit, with the priors.
| ISO | init_stat_est | init_stat_sd | rate_change_est | rate_change_sd | residual_var | r2 |
|---|---|---|---|---|---|---|
| ALB | -2.20 | 1.40 | 0.17 | 0.02 | 6.43 | 0.85 |
| BGD | -7.27 | 3.51 | 0.26 | 0.07 | 59.18 | 0.58 |
| BGR | 0.18 | 1.91 | 0.07 | 0.03 | 13.29 | 0.28 |
| BRB | -3.00 | 1.42 | 0.14 | 0.02 | 6.81 | 0.74 |
| CUB | -1.51 | 0.80 | 0.11 | 0.01 | 1.96 | 0.87 |
| DNK | -2.65 | 1.29 | 0.14 | 0.02 | 5.35 | 0.80 |
| IND | 4.67 | 1.86 | 0.12 | 0.03 | 10.43 | 0.71 |
| NLD | 2.14 | 2.07 | 0.12 | 0.03 | 14.82 | 0.54 |
| PAK | -2.97 | 1.95 | 0.25 | 0.03 | 12.77 | 0.89 |
| ROU | -2.46 | 2.03 | 0.13 | 0.03 | 14.31 | 0.54 |
Yeah for all of these countries the fit has been improved, by visual inspection and the bayes \(R^2\) by disregarding the priors and allowing the model to fit with default priors for each country.